Copper alloy - contg manganese, zinc and lead has improved drilling machineability

摘要

A copper alloy which can be hot rolled contains 8-16% Mn, 20-34% Zn and 1.6-3% Pb. The zinc content is determined by the formula Zn=K-2/3 Mn where K is 30.5-39.3. The lead is uniformly distributed throughout the matrix. Other alloys can be aded to improve strength and corrosion resistance. Less than 0.5% (pref. 0.3%) Al, Fe, Sn, Si, Co, Mg and Co may be added to prevent the formation of undesirable phases and also to aid fabrication. These alloys have improvedmachineability especially drilling machineability and they cna be cold rolled by 40-50% with intermediate annealing stages without cracks appearing at the edges.